Covid-19 mask

Description

Based on Rat_Patrol's design (The face fit part) this filter housing has a larger surface area which allows easier breathing with the suggested filter media (see PDF). I sealed the mask using rubber door seal material attaching it with a hot glue gun. PDF details; The mask is 3D printed using PETG plastic (the same as water bottles) with an added rubber seal “hot glued” to the mask. The filtration media should be the best that you can get and breathe through, it should overlap the mask and be held in place with the retention clip. Fitting for the first time: Without the filtration media or retention cap, place the mask under your chin then offer it to your face, resting on the bridge of the nose, then place the straps over your head, the straps should be sufficiently tight to hold the mask in place with an effective seal. To test the seal, cover the air intake (cling film) and breathe in, if you can feel the mask tighten against your face then it’s sealed, noting the position of the strap, remove the mask and secure the straps in position, It may take a few attempts and require repositioning of the mask (if at anytime you can feel air being exhausted from the side of the mask it will need to be made tighter or repositioned). Subsequent Fitting. Insert filtration media (more on this later). Place straps over your head. Check the seal as before though this time with the filtration media and retention cap in place, If at anytime you can feel air being exhausted or entering from the side of the mask it will need to be made tighter or repositioned. Filtration Media. There is no such thing as a hundred percent effective filtration media for any Covid virus, but sealed HEPA and some medical grade filters are said to work the best, though caution should be used when sourcing HEPA material for filters as some may contain fiberglass which can lead to other respiratory illness. Another point to note, whatever filtration media you decide to use, is that just a one-percent gap in the seal can reduce the filtration efficiency by more than half, which also highlights the need of a sealed mask. There are many reports on the web detailing the best types of filter media to use, I’m following my understanding of the information provided by the American Chemical Society for guidance. With each mask I am providing some 600 count cotton, the report also suggests using chiffon fabric to provide electrostatic filtration. I’d suggest using one layer of the cotton with a layer or two of the chiffon. (If the chiffon is placed outermost it will also stops the cotton moving) Of course I cannot guarantee the effectiveness of either the mask or material provided, and would suggest that social distancing is also adhered to at all times. Wearing As wearing a filtered mask does restrict breathing I would recommend trying it at home for about an hour to get used to wearing it.. If the filtration media you decide to use makes breathing difficult then it could be replaced with a less dense material (for instance 500 count cotton) though this will also reduce the level of protection. If you’ve been using the mask and have come in contact with Covid-19 then the filter will have accumulated a higher concentration of the virus, as there is no easy way to check this it’s best to presume that it has, so the last thing you’d want to do is liberate it! I wouldn't recommend taking it off and replacing it without having first washed both the mask and filter media, if you have multiple places to go to then leave it on for the duration of the trip. Removing. Holding the mask against your face without touching the filter, remove the straps while maintaining the mask in place, once the straps are out of the way slowly remove the mask. I would suggest placing it directly into water, though as a stopgap a resealable bag would suffice, if doing the latter remember the whole interia of the bag is now contaminated. Cleaning. I would suggest immersing the whole mask in hand hot water containing a drop of bleach and washing with washing up liquid, (removing the filter in the water) rinsing thoroughly afterwards, towel dry or leave to dry naturally (though not in a hot place). The filter should be cleaned in the same way and if desired machine washed afterwards. If you have used a bag then this will have to be washed too, in this case do not remove the mask from the bag prior to washing, rather immerse the unopened bag in the washing water, fill with the washing water then remove the mask, washing as above. American Chemical Society - Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks https://pubs.acs.org/doi/abs/10.1021/acsnano.0c03252 Full report: https://pubs.acs.org/doi/suppl/10.1021/acsnano.0c03252/suppl_file/nn0c03252_si_001.pdf

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